When I slowly spiraled into a life that seemed static, lacking emotions and the urge to make friends, I thought I might be a psychopath. Although I was later diagnosed with schizotypal personality disorder, the immediate thought of being a “psychopath” resonated with the whole socially aloof ordeal, which wasn’t the case. The disorder is far too stigmatized, be it because of pop culture or misinformation, and new research by Nanyang Technological University (NTU), Singapore, shows that psychopaths have a key difference in a brain structure that makes them different from the crowd.
Through MRI or magnetic resonance imaging, scientists discovered that the striatum— a portion of the brain linked to reward, motivation, and decision-making— is 10% larger on average in psychopathic individuals. They are bored by the mundane, and they seek reward in the rush of impulse and thrill, making them prone to act eccentrically.
Who Is a Psychopath?
First off, psychopath isn’t a formal medical diagnosis, but a behavioral construct used by researchers and psychologists to define people with antisocial traits and impaired empathy. Often, we put psychopaths and criminals under the same bracket, but that’s not true. Psychopathy is generally associated with an egocentric behavior and a lack of remorse for harmful actions. Research has consistently linked psychopathy with a higher risk of violent behavior, but a psychopath doesn’t necessarily commit crimes.
Psychopaths go to extreme lengths to gratify themselves and seek rewards, often indulging in stimulatory behaviors like substance abuse. Earlier research linked a hyperactive striatum to psychopathy, but it wasn’t clear if the size of the striatum is a risk, too. The study published in The Journal of Psychiatric Research suggests that biology plays a pivotal role in shaping psychopathy, apart from social and environmental experiences.
Risk, Reward, and Striatum
The striatum is part of the basal ganglia, a cluster of neurons located deep in the brain that receives information from the cerebral cortex—the center of thinking, social behavior, and decision-making. Over the past two decades, scientists have begun to link the striatum to social behavior and difficulties in social functioning, rather than simply to reward processing.
By comparing MRI scans with psychopathy assessment results, the researchers found that a larger striatum is responsible for a stronger need for stimulation, including thrill-seeking, excitement, and impulsive behavior. In fact, almost half of the participants with higher striatal volume had psychopathic tendencies.
Professor Adrian Raine from the Departments of Criminology, Psychiatry, and Psychology at the University of Pennsylvania, who co-authored the study, said: “Because biological traits, such as the size of one’s striatum, can be inherited to child from parent, these findings give added support to neurodevelopmental perspectives of psychopathy — that the brains of these offenders do not develop normally throughout childhood and adolescence.”
Psychopathic Traits in People Around Us
The researchers examined a broad group of individuals, from both the community and prison populations, using the Psychopathy Checklist – Revised to identify psychopathic traits in individuals who are not in prisons, but are roaming among us. The female sample, although small, showed for the first time that an enlarged striatum is linked to psychopathy in adult females as much as males. Larger evidence is needed to form a concrete claim; however, the findings suggest that the same brain pattern is not unique to men.
Are Psychopaths Made, or Born?
Typically, the striatum tends to shrink as a child matures, suggesting that brain development likely differs across childhood and adolescence in psychopaths. It is not yet clear whether a person is born with a developmental structural abnormality of the striatum or whether the environment affects its structure. As of now, scientists believe both ‘nature’ and ‘nurture’ have a hand in striatal development.
Although the size of the striatum is examined in this study, antisocial lifestyle and psychopathic traits were linked to reduced volumes in several brain regions, including parts of the thalamus, basal forebrain, pons, cerebellum, and basal ganglia, among other regions.[1] A 2025 study mapped a shared functional brain network, making the case that a network-level view of the brain can yield more insights than a single region.[2] Future studies can link genetics, life experiences, and emotional well-being to striatal development.
I began this article recalling my own experience, and I will end it with one of my realizations. Mental health disorders require a professional diagnosis and should not be based on hunches or ticking boxes. Embrace mental health, and stay happy!
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